Subway transformer



Jan. 10, 1928.

S. HORELICK SUBWAY TRANSFORMER Filed Dec. 17, 1925 Patented Jan. 19,1928.

UNITED srnrss rarest -SAMUEL HORELICK, OF PITTSBURGH, PEHNSYLVANIA,ASSIGNOR TO PITTSBURGH TRANSFORMER COMPANY, 1%. CQIREGEATION OFPENNSYLVANIA.

SUBW AY TRANSFORMER.

Application filed December 17, 1925. Serial No. 75,928. V

This invention relates to a chambered ap paratus having provision forcontrolling the chamber in accordance with various'con ditions. andrelates more particularly to electrical apparatus wherein it is desiredto permit a chamber thereof to have controlled communication with adesired space;

In electrical apparatus, such as a subway transformer, it is desired topermit the transformer interior to have communication with theatmosphere or another equivalent enlarged volume for the purpose ofallowing the transformer to breathe, and thereby to discharge moisturewhich might be present in the insulating oil usually disposed in thechamber. This type of electrical apparatus is placed usually in a pitbelow a normal level, such as a street, from which water may flow withthe possibility of submerging the apparatus. It is of the utmostimportance thatthis Water should not flow into the apparatus.

It is an object of my invention to provide means which will permit theinterior of the apparatus to have communication with a desired space,and which communication will be controlled automatically in accordancewith certain relative conditions existing between said space andchamber. A further object is to provide an improved valve and floatarrangement which will control access to the interior of the apparatus.

Other objects will appear from the follow ing description of theaccompanying draw ings, in whicl Fig. 1 is a sectional view of anenlarged chamber within which a transformer is disposed.

Fig. 2 is an enlarged fragmentary partial sectional view of the valvemechanism.

In the illustrative embodiment of my invention I have shown a desiredspace in the form of an enlarged chamber 1 formed preferably by suitablewalls 2 and to which access may be had through a suitable man hole 3.This manhole is usually flush with the street level, from which watermay flow into the chamber 1. Disposed within the chamber is a piece ofelectrical apparatus, specifically a subway transformer 4, having acover 5 through which air may pass into the transformer interior as byan inverted U-shaped pipe 6. The free end of pipe 6 is provided with asuitable valve housing 7 and a movable valve member 8, which is madeof'suchmaterial and so constructed that no deterioration thereof maytake place or foreign material become lodged therein in case the valveremains inoperative for a great length of time. The parts are providedwith suitable cooperating seat surfaces so that under no conditions willthe valve be held open when the abnormal exterior condition prevails. Toinsure positive closing of valve 8 an arm 9 pivoted thereto carries afloat- 10 which extends a considerable distance below the valve 7 toinsure that considerable leverage will be .nb tained during closingmovements,

As long as chamber 1 does not accumulate water to the extent of engagingthe float 10, chamber 1 will communicate with the transformer interior,thereby permitting the breathing action which is highly beneficial tocertain types of electrical apparatus of the type disclosed. However,upon accumulation of water in the chamber 1 to the extent that it wouldbe detrimental, float 10 will be forced upwardly to close the valve,thereby preventing communication with the transformer interior andaccordingly pre venting flow of water into the same. 0

If the valve should be closed due to action on the float by water whichmight completely submerge the apparatus and should an abnormal pressurecondition arise within the apparatus to such a point that the internalpressure would be greater than the holding force of the float, the valvewould be forced open to relieve this abnormal internal pressurecondition. It is to be noted, however, that the surrounding water couldnot have access to the interior of the apparatus when the valve wasrelieving the abnormal internal pressure for the internal pressure willat all times be great enough to more than overbalance the staticpressure of the surroundingwater. Moreover, the valve is so arrangedthat it could open and close very quickly and thereby further reduce thepossibility of water or other foreign matter gaining access with theinterior.

I claim:

1. In combination with an electrical apparatus having a casing providingan interior chamber, and means forming an 8X- terior chamber, of meansnormally permitting atmospheric communication between said chambers andmeans adapted to inter rupt said communication automatically upon theexistence of an abnormal liquid condition in said exterior chamber.

2. In combination with an electrical apparatus having a chambered casingdisposable in a pit means permitting communication between the pit andcasing chamber, and means for automatically preventing saidcommunication when liquid accumulates in said pit to a predeterminedlevel.

3; In combination with a transformer immersed in oil contained within acasing forming an interior chamber disposed in a pit forming an exteriorchamber, a breather means for said casing normally permitting the escapeof moisture within said casing, liberated from the oil by the heating ofthe oil during the operation of the transformer and means forautomatically sealing said breather means so as to prevent wateraccumulations within said pit from entering said casing when said wateraccumulations rise to a predetermined level.

4. In combination with a transformer immersed in oil contained withina-casing forming an interior chamber disposed in a pit forming anexterior chamber, a breather pipe for said casing normally permittingthe escape of moisture within said casing liber- SAMUEL :HORELICK.

